Home >Backend Development >PHP Tutorial >Principle of image generation and verification code image generation_PHP tutorial

Principle of image generation and verification code image generation_PHP tutorial

WBOY
WBOYOriginal
2016-07-13 10:45:14910browse

This PHP image generation and verification code image generation principle code is supported by the PHP gd library. If your system cannot create images, remove the ";" in front of gd.dll and restart apache. If it is iis, It's OK after starting iis.

This php tutorial image generation and verification code image generation principle code is supported by the php gd library. If your system cannot create images, remove the ";" in front of gd.dll and re- Start apache, if it is iis, restart iis and it will be OK.

$w?$RESIZEWIDTH=$w:$RESIZEWIDTH=400;// 生成图片的宽度
$h?$RESIZEHEIGHT=$h:$RESIZEHEIGHT=400;// 生成图片的高度
function ResizeImage($im,$maxwidth,$maxheight,$name){
    $width = imagesx($im);
    $height = imagesy($im);
    if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
        if($maxwidth && $width > $maxwidth){
            $widthratio = $maxwidth/$width;
            $RESIZEWIDTH=true;//www.bKjia.c0m
        }
        if($maxheight && $height > $maxheight){
            $heightratio = $maxheight/$height;
            $RESIZEHEIGHT=true;
        }
        if($RESIZEWIDTH && $RESIZEHEIGHT){
            if($widthratio < $heightratio){
                $ratio = $widthratio;
            }else{
                $ratio = $heightratio;
            }
        }elseif($RESIZEWIDTH){
            $ratio = $widthratio;
        }elseif($RESIZEHEIGHT){
            $ratio = $heightratio;
        }
        $newwidth = $width * $ratio;
        $newheight = $height * $ratio;
        if(function_exists("imagecopyresampled")){
              $newim = imagecreatetruecolor($newwidth, $newheight);
              imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
        }else{
            $newim = imagecreate($newwidth, $newheight);
              imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
        }
        ImageJpeg ($newim,$name);
        ImageDestroy ($newim);
    }else{
        ImageJpeg ($im,$name);
    }
}
if($_FILES['uploadfile']['size']){
    if($_FILES['uploadfile']['type'] == "image/pjpeg"){
        $im = imagecreatefromjpeg($_FILES['uploadfile']['tmp_name']);
    }elseif($_FILES['uploadfile']['type'] == "image/x-png"){
        $im = imagecreatefrompng($_FILES['uploadfile']['tmp_name']);
    }elseif($_FILES['uploadfile']['type'] == "image/gif"){
        $im = imagecreatefromgif($_FILES['uploadfile']['tmp_name']);
    }
    if($im){
        if(file_exists('bbs.jpg')){
            unlink('www.bKjia.c0m.jpg');
        }
        ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,'bbs.jpg');
        ImageDestroy ($im);
  
    }
}
//$uploadfile="bbs.jpg";

?>

创建图片后记得用ImageDestroy 清空内存哦。

www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/633049.htmlTechArticleThis PHP image generation and verification code image generation principle code is supported by the PHP gd library. If your If the system cannot create pictures, remove the ; in front of gd.dll and restart apache. If it is iis, restart it...
Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn